"It is impossible for an Englishman to open his mouth without making some other Englishman hate or despise him," wrote George Bernard Shaw. During the century since, this country has perennially tried to kid itself that it has shaken off its old fixation with caste. The reassuring claim that we have banished it all to the past was aired on Radio 4 yesterday by rightwing policy wonk, Jill Kirby, who claimed that old divisions had so eroded over the last 20 to 30 years that "class is almost totally irrelevant in modern Britain".

Wednesday's Daily Mail, however, was laced with a strain of class hatred that might have shocked Shaw himself. Mick Philpott, the jobless Derby father who killed six of his children in a house fire, was denounced as a "Vile Product of Welfare UK" in the front-page headline that sat above reportage that simultaneously slighted the large family for having too much money and for being squalidly packed into a "cramped three-bedroom semi". Inside, Jesus biographer AN Wilson discerned a "parable for our age" and casually pronounced that young John, Jack, Jesse and the rest were "killed not only by their father but by the system" of benefits which is too indulgent of the poor, an argument that is of course the moral antithesis of his subject's parable of the vineyard workers.

History is replete with warnings about what can happen when the crimes of individuals are pinned on entire communities. Today's slurring of the whole category of benefit claimants may not pour over into violence on the streets, because the disparate millions who make recourse to benefits do so for myriad reasons, and are not an identifiable community as such. But this sort of coverage nonetheless suggests that – far from being classless – Britain continues to be scarred by class war. The only real question is where the battle lines are drawn, and a new study, which was heavily trailed by the BBC on Wednesday, suggested that the cleavages that count may be shifting.

The old bowler-trilby-flat cap distinction, as parodied by the Two Ronnies and John Cleese, still defines the day-to-day parlance in which people are pigeonholed as upper, middle or working class. But, the new study said, if you factor in friendships, cultural tastes and the great new marker of caste that is food you would get a more variegated picture today. Perhaps – although other sociologists immediately cautioned against a data-driven exercise which, in a fashionable attempt to eschew imposition of any theory of class, moved from asking about tastes for hip-hop and chicken tikka masala to defining social stations in terms of these things. And it seems a safe bet that the new categories thereby contrived – "technical middle class", "emergent service workers" – will never soak far enough into the culture deeply enough to inform the equivalent of Downton Abbey in a century's time. But there was, nonetheless, one firm finding – namely, that an "elite" at the top and an insecure "precariat" at the bottom of the heap both look like becoming classes apart.

The last quarter of the 20th century witnessed an explosion of economic inequality, and – while the long boom may have concealed them for a long time – the big bust is providing occasion for reckoning with the social effects. The US witnessed the same economic trends, and academics there are starting to trace the consequences for non-economic phenomenon such as family breakdown, reporting that even as America's ancient race cleavage heals, its class cleavage is deepening. In the UK, studies of health, education and social mobility have all been pointing towards the persistence of class-bound sclerosis. Now we have we learnt that one can reach the same conclusion even by crunching eccentric numbers on gym membership and Spanish holidays.

So class undoubtedly remains with us. As we discuss what should be done about it, let us hope that we can find ways to discuss it without making some Englishmen despise others.